Computer modeling and electron microscopy of silicon surfaces irradiated by cluster ion impacts

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 202; pp. 261 - 268
• Main Authors: Insepov, Z., Allen, L.P., Santeufemio, C., Jones, K.S., Yamada, I.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2003
• Subjects: AFM; Cluster; Crater; Faceting; Implantation; Molecular dynamics; TEM; 02.70.Ns; Crater; Molecular dynamics; AFM; Cluster; Implantation; 34.50.Dy; 61.43.Bn; TEM; 61.72.Ff; Faceting
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/S0168-583X(02)01867-0

A hybrid molecular dynamics model has been applied for modeling impacts of Ar and decaborane clusters, with energies ranging from 25 to 1500 eV/atom, impacting Si surfaces. Crater formation, sputtering, and the shapes of craters and rims were studied. Our simulation predicts that on a Si(1 0 0), craters are nearly triangular in cross-section, with the facets directed along the close-packed (1 1 1) planes. The Si(1 0 0) craters exhibit four fold symmetry. The craters on Si(1 1 1) surface are well rounded in cross-section and the top-view shows a complicated six fold or triangular image. The simulation results for individual gas cluster impacts were compared with experiments at low dose (10 10 ions/cm 2 charge fluence) for Ar impacts into Si(1 0 0) and Si(1 1 1) substrate surfaces. Atomic force microscopy and cross-sectional high-resolution transmission electron microscope imaging of individual gas cluster ion impacts into Si(1 0 0) and Si(1 1 1) substrate surfaces revealed faceting properties of the craters and are in agreement with the theoretical prediction. The sputtering yield from Si(1 0 0) surfaces bombarded with B 10 cluster ions, with total energy of 1–15 keV, was also calculated. The results of this study will be helpful for the research and development of a new low-damage gas cluster ion beam process technology.